DE102011080934A1 - Method for metallizing polymer layer systems and polymer layer systems - Google Patents

Abstract

The invention provides methods for metallizing polymer layer systems and a corresponding polymer layer systems. The method according to one aspect includes the steps of: forming a layer stack (1, 2, 3; 1, 2, 3 '; 1, 2, 3' '; 1a, 2a, 3a; 1c, 2c, 3c, 3d) with a layer stack Polymer substrate (1; 1a; 1c), a metal foil (3; 3 '; 3' '; 3a; 3c, 3d) and an intervening polymer membrane (2; 2a; 2c); Forming one or more structural regions (6; 6 '' '; 6' '' '; 6a; 6c, 6d) in the metal foil (3; 3'; 3 ''; 3a; 3c, 3d) by means of a first laser irradiation step (FIG. L2, L2 '); and removing the metal foil (3; 3 '; 3' '; 3a; 3c, 3d) from a region which is complementary to the structural region or regions (6; 6' ''; 6 '' '; 6a; 6c, 6d) ( 6 '). According to a further aspect, the method includes the steps of forming a layer stack (1, 2, 3 ', 1, 2, 3' ') with a polymer substrate (1), a structured, at least partially perforated (4, 4') Metal foil (3 ', 3' ') and an intermediate polymer membrane (2); wherein, after forming the layer stack (1, 2, 3 '; 1, 2, 3' '), a laser irradiation step (L1) is performed through a surface (O1) of the polymer substrate (1) facing away from the polymer membrane (2), thereby producing a laser irradiation step Welded connection between the polymer substrate (1) and the polymer membrane (2) is formed; and wherein the polymer membrane (2) in the second laser irradiation step (L1) flows into the perforations (4; 4 ') and forms webs (2a; 2a').

Description

The invention relates to methods for metallizing polymer layer systems and corresponding polymer layer systems.

State of the art

Integrated microfluidic components, e.g. Lab-on-a-chip systems in medical technology often consist of a polymeric multilayer structure with entrapped microfluidic structures, such as e.g. Channels and chambers.

In addition to optical sensor systems as an interface to the outside world, there are increasing efforts to establish integrated on the chip electrical detection systems. This requires an integration of electrical interconnects and contacting possibilities in the polymer layer system. Furthermore, with metallization processes for polymer layer systems u.a. Also, realize electrodes on the channel walls to perform measurements on the fluid in question.

For the metallization of polymers there are a number of methods, e.g. Sputtering, lithographic processes, laser ablation, laser sintering, molded interconnect devices (3D-MID), screen printing with conductive pastes, inkjet processes, etc.

The JP-2004232045 A discloses a sputtering process for sputtering metal films onto a polymer.

Out Sensors and Actuators A 134 (2007), pages 161-168 is an inkjet technique with conductive ink for the metallization of polymers known.

The DE 10 2008 040 882 A1 describes a method for hot stamping printed conductors on polymer substrates. The embossing process is carried out with a metal foil laid on the polymer substrate, which is provided on one side for improved adhesion of the polymer with grown dendrites. During the embossing process, adhesion between the polymer and the metal foil is achieved and at the same time the metal foil is separated at predetermined locations in order to produce an electrically insulated conductor tracks.

The DE 103 50 568 A1 discloses a method of producing film cords and printed circuit board substrates, wherein a thermoplastic plastic film or thermoplastic circuit board or a thermoplastic multilayer with conductor tracks is laser welded to a thermoplastic cover film.

The DE 10 25 570 A1 discloses a method wherein surfaces of plastics are provided with the aid of laser beams with electrical traces.

Disclosure of the invention

The invention provides methods for metallizing polymer layer systems according to claim 1 or 10 and polymer layer systems according to claim 12, 14 and 15, respectively.

Preferred developments are the subject of the respective subclaims.

Advantages of the invention

The present invention makes it possible to integrate metal structure regions by a simple laser welding process into a polymer layer system having a polymer substrate and a polymer membrane. Structured correspondingly, the metal structure regions can serve, for example, as conductor tracks, electrodes, heating structures and contact surfaces, for example for flip-chip contacting of an electrical component.

In a preferred embodiment, by laser transmission welding in a single step, a connection between the metal foil and the polymer membrane and the polymer membrane and the polymer substrate can be created. At the interface between the polymer membrane and the polymer substrate, a laser welding principle joining, i. Heating above the glass transition temperature and mixing of the two materials achieved. Although no mixing takes place at the boundary layer between metal foil and polymer membrane, adhesion (adhesion) is nevertheless obtained.

There is a great advantage in terms of cost and effort compared to the previously known prior art.

In particular, it is possible to use uncoated metal foils, e.g. commercial aluminum foils. There are no special additional materials needed, such as conductive ink in the inkjet process or paste in the screen printing process. Due to the possibility of structuring by laser, no masks or tools that are bound to the printed circuit design are necessary, as is the case with lithography, sputtering or hot stamping.

Since the polymer layers can already be joined by laser transmission welding, it is possible to produce a structured metallization with a few additional steps.

The process is multilayer-capable, ie layers of polymer membrane and structured metal foil can alternate. There are no appreciable restrictions on the feasible geometry of the structuring. In the case of the above-mentioned hot stamping of printed conductors, for example, curvatures of printed conductors are problematic, which is not the case with the present invention.

The thickness of the metal foil can be adapted over a wide range to the appropriate application.

Corresponding metallized surfaces can locally influence biochemical reactions, for example in a Lab-on-a-Chip, e.g. by flowing a current or acting as a catalyst.

In general, the systems according to the invention have the further advantage that the connection of the metal foil over the polymer membrane with the polymer substrate automatically ensures stress decoupling of the conductor tracks on account of the flexibility of the polymer membrane. So it can be ensured that electrical contacts or traces or similar. also remain undamaged when passing through temperature cycles.

In contrast to the subject of DE 10 25 570 A1 For example, a laser-based structuring of the metal foil can take place after bonding to the polymer surface. This eliminates the problem of aligning a previously structured metal foil with respect to the underlying surface. This makes it possible, for example, to align conductor tracks to channels and cavities present in the polymer very precisely.

Brief description of the drawings

Further features and advantages of the present invention will be explained below with reference to embodiments with reference to the figures.

Show it:

1a) -D) schematic views for explaining a method for metallizing polymer layer systems according to a first embodiment of the present invention, namely 1a) and b) in cross section and 1c) and d) in plan view of the metallized area;

2a) -C) are schematic views for explaining a method for metallizing polymer layer systems according to a second embodiment of the present invention, namely 2a) and b) in cross section and 2c) in view of the metallized area;

3 a schematic cross-sectional view for explaining a method for metallizing polymer layer systems according to a third embodiment of the present invention;

4 a schematic cross-sectional view for explaining a method for metallizing polymer layer systems according to a fourth embodiment of the present invention;

5 a schematic cross-sectional view for explaining a polymer layer system according to a fifth embodiment of the present invention;

6 a schematic cross-sectional view for explaining a polymer layer system according to a sixth embodiment of the present invention;

7 a schematic cross-sectional view for explaining a polymer layer system according to a seventh embodiment of the present invention;

8a) D) schematic cross-sectional views for explaining a polymer layer system according to an eighth embodiment of the present invention; and

9a) -C) are schematic cross-sectional views for explaining a polymer layer system according to a ninth embodiment of the present invention.

Embodiments of the invention

In the figures, like reference numerals designate the same or functionally identical elements.

1a) -D) are schematic views for explaining a method for metallizing polymer layer systems according to a first embodiment of the present invention, namely 1a) and b) in cross section and 1c) and d) in plan view of the metallized area.

In 1a) denotes reference numeral 1 a transparent polymer substrate, 2 a light absorbing polymer membrane and 3 a metal foil.

From the polymer substrate 1 , the polymer membrane 2 and the metal foil 3 a layer stack is formed on a base U. The interface between the metal foil 3 and the polymer membrane 2 is designated by reference AL, whereas the interface between polymer membrane 2 and polymer substrate 1 marked with the reference AM. Reference symbol O1 denotes that of the polymer membrane 2 remote surface of the polymer substrate 1 ,

As a polymer substrate 1 For example, thermoplastics such as PC, PP, PE, PMMA, COP, COC etc. can be used. Suitable polymer membranes are thermoplastic elastomers and thermoplastics. Aluminum foil, copper foil, gold foil, silver foil etc. are suitable as metal foil.

Exemplary dimensions in the layer stack are a thickness of the polymer substrate 1 between 0.5 and 3 mm, a thickness of the polymer membrane 2 between 25 and 300 microns and a thickness of the metal foil 3 between 5 and 500 μm. The width of the track 6 is typically 20 μm to 5 mm. The lateral dimension of the structure according to 1a) is for example 10 × 10 to 100 × 100 mm ² .

In the process state according to 1a) a laser irradiation step L1 is performed by that of the polymer membrane 2 opposite surface O1 of the polymer substrate 1 , whereby a welded joint between the polymer substrate 1 and the polymer membrane 2 arises. During the laser irradiation step L1, the polymer membrane becomes 2 and the adjacent polymer substrate 1 liquefied, and the mixing and interdiffusion of macromolecules creates a welded joint or joint. At the same time, in this laser irradiation step L1, adhesion (adhesion) between the metal foil is combined with a predetermined contact pressure 3 and the polymer membrane 2 reached.

To the adhesion between the metal foil 3 and the polymer membrane 2 can increase before the formation of the layer stack 1 . 2 . 3 a plasma cleaning or activation of the surfaces of polymer membrane 2 and metal foil 3 be carried out at the interface AL. Alternatively or additionally, a roughening of the metal foil 3 be performed at the interface AL, for example, with a corresponding laser treatment.

Improved adhesion can also be achieved by using metal foils which have been specially coated, e.g. with sealing wax, adhesive (eg Resin-Coated Copper RCC) or with grown dendritic structures (electroplating) or black oxide coating.

Continue with reference to 1b) becomes the layer stack 1 . 2 . 3 in the connected state after the laser irradiation step L1 on the base U turned over and another laser treatment step L2 on the polymer membrane 2 opposite surface O2 of the metal foil 3 carried out. In an alternative embodiment, the laser treatment step L2 can also be done by another laser from the bottom, without turning around is required.

The laser treatment step L2 becomes one or more structural areas 6 in the metal foil 3 formed, for example, conductor tracks. The laser beam bypasses the structural area 6 and forms at its edge a corresponding cutting line LL in the metal foil 3 along which the metal foil 3 is severed. The state after completion of the laser treatment step L2 is in 1c) shown.

Continue with reference to 1d) can be the to the structural area 6 in the form of the conductor track complementary area 6 ' remove the metal foil after completion of the laser treatment step L2 and thus remove. So that the polymer membrane 2 remains undamaged when peeling, the adhesion of the full-surface connection along the boundary surface AL in stacking must be selected accordingly.

The final state with the structure area 6 in the form of the track on the polymer membrane 2 after removing the complementary area 6 ' is in 1d) shown.

In an alternative embodiment, only the structural area may be during the laser treatment step L1 6 are heated, which should remain metallized after the laser treatment step L2. In this way, the complementary area dissolves 6 ' after the step L2 immediately from the surface and there is no additional step necessary to remove the excess metal foil 3 deducted. In this procedure, it is possible that in step L2, the polymer membrane 2 is severed and the polymer membrane 2 together with metal foil 3 in the complementary area 6 ' replaces. In order to prevent this (the polymer membrane can fulfill further functions), a layer structure consisting of polymer substrate can initially be used 1 and polymer membrane 2 with laser transmission welding on all areas of the polymer substrate 1 and then the metallization process are performed by the metal foil 3 on the polymer membrane 2 is hung up and only the structural area 6 is heated in the laser treatment step L1.

2a) -C) are schematic views for explaining a method for metallizing polymer layer systems according to a second embodiment of the present invention, namely 2a) and b) in cross section and 2c) in plan view of the metallized area.

As in 2a) is shown in the second embodiment, a transparent clamping device 15a . 15b , For example, in the form of two corresponding transparent plates, provided to the layer stack 1 . 2 . 3 during the laser treatment step L1 clamp and thus to make the adhesion or the weld more stable.

According to 2 B) For example, the laser treatment step L2 'in the second embodiment is performed differently from the first embodiment. In particular, in the second embodiment laser ablation of the complementary region takes place in the laser treatment step L2 ' 6 ' what finally to in 2c) shown state leads.

The adhesion of the structural area 6 in the form of the conductor can be adjusted as needed by using different irradiation intensities or irradiation grid as in the first embodiment.

3 FIG. 12 is a schematic cross-sectional view for explaining a method of metallizing polymer layer systems according to a third embodiment of the present invention. FIG.

In the third embodiment according to 3 is the state immediately after the laser treatment step L1 for creating the welded joint between polymer substrate 1 and polymer membrane 2 shown.

In this third embodiment, the metal foil 3 ' before the formation of the layer stack 1 . 2 . 3 ' with perforations 4 , For example, holes provided. Such perforations 4 can be provided either over the entire surface or only in certain areas, where later increased adhesion is desired, for example, only in the conductor track areas.

The diameter of the holey structures with the perforations 4 in the metal foil 3 ' be for example 5 to 200 microns.

During the laser treatment step L1, the polymer membrane liquefies 2 and spreads through the perforations 4 in the form of bars 2a out. After cooling, these webs provide 2a for a reinforced connection between the metal foil 3 ' and the polymer membrane 2 ,

For example, the perforations can be 4 according to 3 by a corresponding punching process in the metal foil 3 ' contribute.

4 FIG. 12 is a schematic cross-sectional view for explaining a method of metallizing polymer layer systems according to a fourth embodiment of the present invention. FIG.

In the fourth embodiment according to 4 are the perforations with reference numerals 4 ' and the webs with reference numerals 2a ' designated and were by means of a laser in the metal foil 3 '' brought in. By this type of laser perforation of the metal foil 3 '' from that of the polymer membrane 2 turned away side crater-shaped or conical perforations arise 4 ' which is that of the polymer membrane 2 Widen the opposite side, resulting in a further improved connection between metal foil 3 '' and polymer membrane 2 results.

The diameter of the holey structures with the perforations 4 ' in the metal foil 3 '' For example, also be 5 to 200 microns.

5 FIG. 12 is a schematic cross-sectional view for explaining a method of metallizing polymer film systems according to a fifth embodiment of the present invention. FIG.

In the fifth embodiment according to 5 became the metal foil 3 ' after the execution of the laser treatment step L1, starting from the state according to FIG 3 to a corresponding trace 6 ''' structured. Because the perforations 4 only in the area of the track 6 ''' are provided, the complementary area settled 6 ' simply remove after the laser treatment step L2.

6 FIG. 12 is a schematic cross-sectional view for explaining a polymer layer system according to a sixth embodiment of the present invention. FIG.

In the sixth embodiment, the in 5 5 shows a polymer substrate lid additionally shown 10 on the side with the structured trace 6 ''' first applied and then welded, which can be achieved for example by a device with welding stamp or also with laser transmission welding. Duch a corresponding contact pressure of the polymer substrate cover 10 can the conductor track 6 ''' in the polymer membrane 2 be pressed so that when connected to the Polymerubstratdeckel 10 no air pockets arise. Due to the perforations 4 this results also in the areas of the conductor track 6 ''' a real weld, as the polymer membrane 2 with the polymer substrate lid 10 there in the molten state can mix and connect.

Without using the perforations 4 This would result in a join only in areas where there is direct contact between the polymer membrane 2 and polymer substrate lids 10 is present.

7 FIG. 12 is a schematic cross-sectional view for explaining a polymer film system according to a seventh embodiment of the present invention. FIG.

In the seventh embodiment according to 7 became the metal foil 3 '' after the execution of the laser treatment step L1, starting from the state according to FIG 4 to a corresponding trace 6 '''' structured. Because the perforations 4 ' only in the area of the track 6 '''' are provided, the complementary area settled 6 ' simply remove after the laser treatment step L2.

8a) -D) are schematic cross-sectional views for explaining a polymer layer system according to an eighth embodiment of the present invention, which illustrates the realization of a via in a polymer layer system.

According to 8a) becomes a layer stack 1a . 2a . 3a with a polymer substrate 1a one above the polymer substrate 1a arranged first polymer membrane 2a and one over the first polymer membrane 2a arranged first conductor track 6a from a first metal foil 3a made, for example, by the method according to 1a) - 1d) he follows.

In a further process step, which in 8b) is illustrated above the first polymer membrane 2a and the first trace 6a a second polymer membrane 2 B formed and above the first trace 6a a contact hole 14a in the second polymer membrane 2 B created. Subsequently, a second conductor track 6b from a second metal foil 3b on the second polymer membrane 2 B and above the contact hole 14a generated.

Regarding 8c) becomes a polymer substrate lid 10a which is an increase 14 having.

Add the polymer substrate lid 10a with the raised area 14 according to 8c) with the in 8b) represented structure, so form the first trace 6a and the second trace 6b over the elevated area 14 through the contact hole 14a a contact K, as in 8d) shown.

To further improve the contact K can in the region of the contact K on the first conductor 6a electrically conductive adhesives are used, which are applied for example by dispensing or screen printing. Likewise it is possible on the first trace 6a apply a solder in the region of the contact K and heat the polymer layer system during joining above the melting temperature of the solder. Alternatively, a direct welding of the two conductor tracks 6a . 6b in the region of the contact K by means of a laser.

9a) -C) are schematic cross-sectional views for explaining a polymer layer system according to a ninth embodiment of the present invention, which illustrates the realization of a thermocouple in a polymer layer system.

Regarding 9a) becomes a layer stack 1c . 2c . 3c . 3d formed, which is a polymer substrate 1c , one above the polymer substrate 1c arranged first polymer membrane 2c and one over the first polymer membrane 2c arranged first conductor track 6c from a first metal foil 3c and a second conductor track arranged above the first polymer membrane 6d comprising a second metal foil.

The first and second trace 6c . 6d are in the central region of the polymer substrate 1c arranged overlapping and bind there a thermocouple contact 16 , The arrangement according to 9a) can be prepared for example by the method according to any one of claims 1a) -d).

The tracks 6c . 6d exist to form a corresponding thermal voltage across the thermocouple contact 16 from suitable metal pairs, such as. NiCr / Ni, FeCu / Ni, Cu / CuNi etc.

Furthermore, according to 9b) a polymer substrate lid 10b provided, which is a cavity 15 having. Over the polymer substrate lid 10b and the cavity 15 arranged is a second polymer membrane 2d ,

Regarding 9c) becomes the polymer substrate lid 10b with the cavity 15 arranged on the layer stack such that the cavity 15 in the area of the thermocouple contact 16 is arranged. The cavity 15 is for example part of a microfluidic channel in which the temperature is to be determined.

Often, accurate temperature determination within a lab-on-a-chip system is of great interest. In this case, for example, there has hitherto been the problem that miniaturized temperature sensors, such as thermocouples or resistance thermometers, can only be integrated poorly into the polymeric environment and good thermal contact through proximity to the corresponding cavity is often associated with the risk of leakage. The ninth embodiment described above has the advantage that the temperature measuring point only by a very thin polymer membrane 2c , for example, with a thickness of 25 microns, from the cavity 15 is separated and thus an optimal thermal contact with the cavity 15 with the Target temperature has. In addition, by joining the polymer membranes 2c . 2d with each other or with the polymer substrate 1c and the polymer substrate cover 10b the tightness of the described arrangement ensured.

Experiments have shown that thermocouples produced in this way provide reliable measured values that match those achievable by conventional thermocouples.

Although the present invention has been described in terms of preferred embodiments, it is not limited thereto. In particular, the materials and topologies mentioned are only examples and not limited to the illustrated examples.

For example, over the structure according to 1d) Another polymer membrane and metal foil are welded and structured. For self-adhesive metal foils, this is possible without restriction. When using an embodiment of the metal foil that requires laser welding to bond between the polymer membrane and the metal foil, it should be noted that an additional trace level should not be placed in the shadow (relative to the laser beam) of a previously created pattern. For two traces, however, two subsystems, as in can be prepared, which are then welded with an additional polymer membrane between the metal foils.

The above-mentioned methods for metallizing polymer layer systems can generally also be used if the joining of polymer membrane and polymer substrate is carried out using other techniques, such as e.g. Gluing or ultrasonic welding, was carried out before the formation of the layer stack with the metal foil.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2004232045 A [0005]
• DE 102008040882 A1 [0007]
• DE 10350568 A1 [0008]
• DE 1025570 A1 [0009, 0021]

Cited non-patent literature

• Sensors and Actuators A 134 (2007), pages 161 to 168 [0006]

Claims (15)

Method for metallizing polymer layer systems, comprising the steps of: forming a layer stack ( 1 . 2 . 3 ; 1 . 2 . 3 '; 1 . 2 . 3 ''; 1a . 2a . 3a ; 1c . 2c . 3c . 3d ) with a polymer substrate ( 1 ; 1a ; 1c ), a metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) and an intermediate polymer membrane ( 2 ; 2a ; 2c ); Forming one or more structural areas ( 6 ; 6 '''; 6 ''''; 6a ; 6c . 6d ) in the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) by means of a first laser irradiation step (L2, L2 '); and removing the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) from one to the structural area (s) ( 6 ; 6 '''; 6 ''''; 6a ; 6c . 6d ) complementary area ( 6 ' ). The method of claim 1, wherein a second laser irradiation step (L1) is performed by one of the polymer membrane (FIG. 2 ; 2a . 2c ) facing away from surface (O1) of the polymer substrate ( 1 ; 1a ; 1c ), whereby a welded joint between the polymer substrate ( 1 ; 1a ; 1c ) and the polymer membrane ( 2 ; 2a ; 2c ) and an adhesion between the polymer membrane ( 2 ; 2a ; 2c ) and the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) arises. Method according to claim 2, wherein the layer stack ( 1 . 2 . 3 ; 1 . 2 . 3 '; 1 . 2 . 3 ''; 1a . 2a . 3a ; 1c . 2c . 3c . 3d in the second laser treatment step (L1) into a laser irradiation transparent clamping device ( 15a . 15b ) is clamped. The method of claim 1, 2 or 3, wherein in the first laser irradiation step (L2) a laser beam on a polymer membrane facing away from the top (O2) of the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) and corresponding cut lines (LL) in the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ). The method of claim 1, 2 or 3, wherein in the first laser irradiation step (L2) a laser beam on a polymer membrane facing away from the top (O2) of the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) and to the structural area (s) ( 6 ; 6 '''; 6 ''''; 6a ; 6c . 6d ) complementary area ( 6 ' ) and wherein the one or more structural regions ( 6 ; 6 '''; 6 ''''; 6a ; 6c . 6d ) on the polymer membrane ( 2 ; 2a ; 2c ) remain. Process according to claim 1, wherein the polymer substrate ( 1 ; 1a ; 1c ) before forming the layer stack ( 1 . 2 . 3 ; 1 . 2 . 3 '; 1 . 2 . 3 ''; 1a . 2a . 3a ; 1c . 2c . 3c . 3d ) with the polymer membrane ( 2 ; 2a ; 2c ) is connected. The method of claim 6, wherein a second laser irradiation step (L1) is performed by one of the polymer membrane (FIG. 2 ; 2a . 2c ) facing away from surface (O1) of the polymer substrate ( 1 ; 1a ; 1c ) is carried out in such a way that an adhesion between the polymer membrane ( 2 ; 2a ; 2c ) and the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) only in the one or more structural areas ( 6 ; 6 '''; 6 ''''; 6a ; 6c . 6d ) in the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) arises. Method according to claim 2, wherein in the metal foil ( 3 ; 3 '; 3 ''; 3a ; 3c . 3d ) at least partially perforations ( 4 ; 4 ' ) into which the polymer membrane ( 2 ; 2a ; 2c ) at the second laser irradiation step (L1). Method according to claim 8, wherein the perforations ( 4 ' ) are cone-shaped and the cones of the polymer membrane ( 2 ; 2a ; 2c ) spread groundbreaking. Method for metallizing polymer layer systems, comprising the steps of: forming a layer stack ( 1 . 2 . 3 '; 1 . 2 . 3 '' ) with a polymer substrate ( 1 ), a structured, at least partially with perforations ( 4 ; 4 ' ) provided metal foil ( 3 '; 3 '' ) and an intermediate polymer membrane ( 2 ); wherein after forming the layer stack ( 1 . 2 . 3 '; 1 . 2 . 3 '' ) a laser irradiation step (L1) through one of the polymer membrane ( 2 ) facing away from surface (O1) of the polymer substrate ( 1 ), whereby a welded joint between the polymer substrate ( 1 ) and the polymer membrane ( 2 ) arises; and wherein the polymer membrane ( 2 ) at the laser irradiation step (L1) in the perforations ( 4 ; 4 ' ) flows in and webs ( 2a ; 2a ' ) trains. Method according to claim 10, wherein the perforations ( 4 ' ) are cone-shaped and the cones of the polymer membrane ( 2 ) spread groundbreaking. Polymer layer system comprising: a layer stack ( 1 . 2 . 3 '; 1 . 2 . 3 '' ) with a polymer substrate ( 1 ), a structured, at least partially with perforations ( 4 ; 4 ' ) provided metal foil ( 3 '; 3 '' ) with one or more structural areas ( 6 '''; 6 '''' ) and an intermediate polymer membrane ( 2 ); a welded connection between the polymer substrate ( 1 ) and the polymer membrane ( 2 ); and wherein the polymer membrane ( 2 ) in the perforations ( 4 ; 4 ' ). Polymer layer system according to claim 12, wherein the perforations ( 4 ' ) are cone-shaped and the cones of the polymer membrane ( 2 ) spread groundbreaking. Polymer layer system comprising: a layer stack ( 1a . 2a . 3a ) with a polymer substrate ( 1a ), one above the polymer substrate ( 1a ) arranged first polymer membrane ( 2a ) and one over the first polymer membrane ( 2a ) arranged first conductor track ( 6a ) from a first metal foil ( 3a ), preferably prepared by the process according to any one of claims 1 to 9; and one above the first track ( 6a ) arranged second polymer membrane ( 2 B ) with a contact hole ( 14a ) and one over the second polymer membrane ( 2 B ) and the contact hole ( 14a ) arranged second track ( 6b ) from a second metal foil ( 3b ); and a polymer substrate cover ( 10a ) with a raised area ( 14 ), which in such a way on the second conductor track ( 6b ) and the second polymer membrane ( 2 B ) is arranged that the first conductor track ( 6a ) and the second conductor track ( 6b ) above the raised area ( 14 ) through the contact hole ( 14a ) form a contact (K). Polymer layer system comprising: a layer stack ( 1c . 2c . 3c . 3d ) with a polymer substrate ( 1c ), one above the polymer substrate ( 1c ) arranged first polymer membrane ( 2c ) and one over the first polymer membrane ( 2c ) arranged first conductor track ( 6c ) from a first metal foil ( 3c ) and one over the first polymer membrane ( 2c ) arranged second conductor track ( 6d ) from a second metal foil ( 3d ), wherein the first and second conductor track ( 6c . 6d ) a thermocouple contact ( 16 ), preferably prepared by the process according to any one of claims 1 to 9; and a polymer substrate cover ( 10b ), which has a cavity ( 15 ), with an over the polymer substrate cover ( 10b ) and the cavity ( 15 ) arranged second polymer membrane ( 2d ); the polymer substrate cover ( 10b ) on the layer stack ( 1c . 2c . 3c . 3d ) is arranged that the cavity ( 15 ) in the area of the thermocouple contact ( 16 ) is arranged.

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